Electric power is generated by converting one form of energy into electrical energy. In a thermal power plant, thermal energy is converted into electrical energy. Known thermal power plants include a boiler unit, fed by water for steam and fuel-oxygen for heat energy, including one or more furnaces and water circulation systems. The steam produced by the boiler is passed through one or more super-heaters and then to the turbine through the throttle valves. After passing through the high pressure turbine, the steam loses thermal and pressure energy which is further regained by passing it through super heaters. The steam is then passed through intermediate and low pressure turbines to ensure full utilization. Finally, the steam is condensed reheated and circulated back to the boiler through feed water pump. Electrical generators, synchronized to an electric grid, can be shafted to the turbines and thus electrical power is generated.
The plant is controlled by distributed control system (DCS) and is operated in various modes. The modes of thermal power plant control can be Manual mode, Boiler follow mode, Turbine follow mode, and coordinated mode. While coordinated mode and Turbine follow mode can be the ones used during normal plant operation. Exemplary embodiments of the present disclosure relate to the plant control optimization and fault detection during these modes.
Turbine suppliers furnish data sheets based on designs having different power generation specifications (expressed in Mega Watt, MW) and these data sheet specifications serve as input parameters for plant startup operation. The specifications of the datasheets are not generally used on a continuous basis by the DCS to provide set-points for the key process values e.g., throttle pressure, throttle temperature, reheat temperature and drum level. Such datasheet specifications serve as a baseline to gauge the performance of the plant. Thus, there is a potential for datasheet specifications being integrated with the DCS for better control of the plant and to track performance.
Further, in the scenario where the difference in MW generation and the demand is significant, the time taken to reach the demand can be considerably high. Control procedures should provide for optimization with regard to the time taken by the plant to adjust itself to meet the demand.
Scenarios of control procedures during a demand change and its effect, specifically on a degraded plant (e.g., a degraded furnace) can be illustrated to indicate improvement/optimization of the parameters in control and fault analysis.